Add attendee transformation workflows

MeetingAssistant.Tests/MeetingScreenshotServiceTests.cs

@@ -1,6 +1,7 @@
 using MeetingAssistant.MeetingNotes;
 using MeetingAssistant.Screenshots;
 using MeetingAssistant.Speakers;
+using MeetingAssistant.Workflow;
 using Microsoft.Extensions.Logging.Abstractions;
 using Microsoft.Extensions.Options;
 using System.Drawing;
@@ -167,6 +168,35 @@ public sealed class MeetingScreenshotServiceTests
             request.SequenceEqual(["Ada Lovelace", "Ada L.", "Grace Hopper", "Ada Lovelace"]));
     }
 
+    [Fact]
+    public async Task CaptureTransformsOcrAttendeesBeforeWritingMeetingNote()
+    {
+        var fixture = await ScreenshotFixture.CreateAsync(
+            options =>
+            {
+                options.Screenshots.Ocr.Enabled = true;
+            });
+        var workflowEngine = new TransformingAttendeeWorkflowEngine("Ada Lovelace (Contoso)", "Ada Lovelace");
+        var service = fixture.CreateService(
+            new FixedScreenshotCapture([1, 2, 3]),
+            new CapturingScreenshotOcrClient(
+                "Visible participant tile: Ada.",
+                attendees: ["Ada Lovelace (Contoso)"]),
+            meetingWorkflowEngine: workflowEngine);
+
+        await service.CaptureAsync(
+            fixture.Artifacts,
+            DateTimeOffset.Parse("2026-05-26T10:00:00+02:00"),
+            DateTimeOffset.Parse("2026-05-26T10:00:10+02:00"),
+            fixture.Options,
+            CancellationToken.None);
+        await service.WaitForPendingOcrAsync(fixture.Artifacts, TimeSpan.FromSeconds(5), CancellationToken.None);
+
+        var meeting = await fixture.NoteStore.ReadAsync(fixture.Artifacts.MeetingNotePath, CancellationToken.None);
+        Assert.Equal(["Ada Lovelace"], meeting.Frontmatter.Attendees);
+        Assert.Equal(["Ada Lovelace (Contoso)"], workflowEngine.AttendeeRequests);
+    }
+
     [Fact]
     public async Task CaptureWritesRetryLinkWhenOcrFails()
     {
@@ -423,7 +453,8 @@ public sealed class MeetingScreenshotServiceTests
         public MeetingScreenshotService CreateService(
             IActiveWindowScreenshotCapture capture,
             IScreenshotOcrClient ocrClient,
-            ISpeakerIdentityAttendeeCanonicalizer? attendeeCanonicalizer = null)
+            ISpeakerIdentityAttendeeCanonicalizer? attendeeCanonicalizer = null,
+            IMeetingWorkflowEngine? meetingWorkflowEngine = null)
         {
             return new MeetingScreenshotService(
                 capture,
@@ -431,7 +462,8 @@ public sealed class MeetingScreenshotServiceTests
                 NoteStore,
                 attendeeCanonicalizer ?? PassthroughSpeakerIdentityAttendeeCanonicalizer.Instance,
                 ocrClient,
-                NullLogger<MeetingScreenshotService>.Instance);
+                NullLogger<MeetingScreenshotService>.Instance,
+                meetingWorkflowEngine);
         }
     }
 

MeetingAssistant.Tests/MeetingSummaryToolTests.cs

@@ -293,6 +293,44 @@ public sealed class MeetingSummaryToolTests
         Assert.Contains("transcript: \"[[../Transcripts/transcript|Transcript]]\"", meetingNote);
     }
 
+    [Fact]
+    public async Task ToolsTransformAddedAttendeeBeforeWritingMeetingNote()
+    {
+        var root = Path.Combine(Path.GetTempPath(), "meeting-assistant-tests", Guid.NewGuid().ToString("N"));
+        var artifacts = new MeetingSessionArtifacts(
+            MeetingNotePath: Path.Combine(root, "Meetings", "Notes", "meeting.md"),
+            TranscriptPath: Path.Combine(root, "Meetings", "Transcripts", "transcript.md"),
+            AssistantContextPath: Path.Combine(root, "Meetings", "Assistant Context", "context.md"),
+            SummaryPath: Path.Combine(root, "Meetings", "Summaries", "summary.md"));
+        Directory.CreateDirectory(Path.GetDirectoryName(artifacts.MeetingNotePath)!);
+        await File.WriteAllTextAsync(
+            artifacts.MeetingNotePath,
+            """
+            ---
+            title: Meeting
+            attendees: []
+            projects: []
+            transcript: "[[../Transcripts/transcript|Transcript]]"
+            assistant_context: "[[../Assistant Context/context|Assistant Context]]"
+            summary: "[[../Summaries/summary|Summary]]"
+            ---
+
+            User note line.
+            """);
+        var workflowEngine = new TransformingAttendeeWorkflowEngine("Ada Lovelace (Contoso)", "Ada Lovelace");
+        var tools = new MeetingSummaryTools(
+            artifacts,
+            new MeetingAssistantOptions(),
+            meetingWorkflowEngine: workflowEngine);
+
+        Assert.Equal("Added attendee Ada Lovelace.", await tools.AddAttendee("Ada Lovelace (Contoso)"));
+
+        var meetingNote = await File.ReadAllTextAsync(artifacts.MeetingNotePath);
+        Assert.Contains("- Ada Lovelace", meetingNote);
+        Assert.DoesNotContain("Ada Lovelace (Contoso)", meetingNote);
+        Assert.Equal(["Ada Lovelace (Contoso)"], workflowEngine.AttendeeRequests);
+    }
+
     [Fact]
     public async Task ToolsOverrideSpeakerInTranscriptAndRecordOverride()
     {
@@ -799,4 +837,5 @@ public sealed class MeetingSummaryToolTests
         Assert.False(tools.SummaryWasWritten);
         Assert.False(File.Exists(artifacts.SummaryPath));
     }
+
 }

MeetingAssistant.Tests/MeetingWorkflowEngineTests.cs

@@ -310,6 +310,10 @@ public sealed class MeetingWorkflowEngineTests
     [InlineData("speaker_identified:\n        name: ADA", "speaker", null, null, "ada", true)]
     [InlineData("speaker_identified:\n        name: Ada", "speaker", null, null, "Grace", false)]
     [InlineData("speaker_identified: {}", "speaker", null, null, "Grace", true)]
+    [InlineData("attendee_added:\n        equals: Ada Lovelace", "attendee", null, null, "ada lovelace", true)]
+    [InlineData("attendee_added:\n        contains: contoso", "attendee", null, null, "Ada (Contoso)", true)]
+    [InlineData("attendee_added:\n        regex: '^Ada .+Contoso\\)$'", "attendee", null, null, "Ada (Contoso)", true)]
+    [InlineData("attendee_added:\n        regex: '^Grace'", "attendee", null, null, "Ada (Contoso)", false)]
     public async Task TriggerMatchingScenarios(
         string triggerYaml,
         string eventKind,
@@ -318,6 +322,16 @@ public sealed class MeetingWorkflowEngineTests
         string? speaker,
         bool shouldRun)
     {
+        var stepYaml = eventKind == "attendee"
+            ? """
+                - uses: set_property
+                  property: attendee.name
+                  value: Triggered
+            """
+            : """
+                - uses: add_project
+                  value: Triggered
+            """;
         var fixture = await WorkflowFixture.CreateAsync(
             $$"""
             rules:
@@ -325,14 +339,21 @@ public sealed class MeetingWorkflowEngineTests
               on:
                 - {{triggerYaml}}
               steps:
-                - uses: add_project
+            {{stepYaml}}
-                  value: Triggered
             """);
 
-        await fixture.Engine.RunAsync(
+        var workflowEvent = CreateEvent(eventKind, fixture.Artifacts, from, to, speaker);
-            CreateEvent(eventKind, fixture.Artifacts, from, to, speaker),
+        if (eventKind == "attendee")
-            fixture.Options,
+        {
-            CancellationToken.None);
+            var transformed = await fixture.Engine.TransformAttendeeAsync(
+                workflowEvent,
+                fixture.Options,
+                CancellationToken.None);
+            Assert.Equal(shouldRun ? "Triggered" : speaker, transformed);
+            return;
+        }
+
+        await fixture.Engine.RunAsync(workflowEvent, fixture.Options, CancellationToken.None);
 
         var meeting = await fixture.ReadMeetingAsync();
         Assert.Equal(shouldRun, meeting.Frontmatter.Projects.Contains("Triggered"));
@@ -603,6 +624,34 @@ public sealed class MeetingWorkflowEngineTests
         Assert.Equal(["Ada Lovelace"], meeting.Frontmatter.Attendees);
     }
 
+    [Fact]
+    public async Task AttendeeAddedRuleCanTransformWorkflowAddedAttendee()
+    {
+        var fixture = await WorkflowFixture.CreateAsync(
+            """
+            rules:
+            - name: add-raw-attendee
+              on:
+                - created: {}
+              steps:
+                - uses: add_attendee
+                  value: 'Ada Lovelace (Contoso)'
+            - name: clean-contoso-attendee
+              on:
+                - attendee_added:
+                    contains: 'Contoso'
+              steps:
+                - uses: set_property
+                  property: attendee.name
+                  value: '@Model.Attendee.Name.Replace(" (Contoso)", "")'
+            """);
+
+        await RunCreatedAsync(fixture);
+
+        var meeting = await fixture.ReadMeetingAsync();
+        Assert.Equal(["Ada Lovelace"], meeting.Frontmatter.Attendees);
+    }
+
     [Fact]
     public async Task AddAttendeeDoesNotDuplicateExistingDisplayNameFromEmailAddress()
     {
@@ -792,6 +841,7 @@ public sealed class MeetingWorkflowEngineTests
         {
             "created" => MeetingWorkflowEvent.Created(artifacts),
             "speaker" => MeetingWorkflowEvent.SpeakerIdentified(artifacts, speaker ?? "Ada"),
+            "attendee" => MeetingWorkflowEvent.AttendeeAdded(artifacts, speaker ?? "Ada"),
             "state" => MeetingWorkflowEvent.StateTransition(
                 artifacts,
                 ParseState(from ?? "collecting metadata"),

MeetingAssistant.Tests/RecordingCoordinatorTests.cs

@@ -900,6 +900,39 @@ public sealed class RecordingCoordinatorTests
         await coordinator.StopAsync(CancellationToken.None);
     }
 
+    [Fact]
+    public async Task StartTransformsMetadataAttendeesBeforeWritingNote()
+    {
+        var audioSource = new ControlledAudioSource();
+        var noteStore = new InMemoryMeetingNoteStore("C:\\Vault\\Meetings\\Notes\\metadata-meeting.md");
+        var workflowEngine = new TransformingAttendeeWorkflowEngine("Ada Lovelace (Contoso)", "Ada Lovelace");
+        var coordinator = new MeetingRecordingCoordinator(
+            audioSource,
+            new TestSpeechRecognitionPipelineFactory(new EchoStreamingTranscriptionProvider()),
+            new InMemoryTranscriptStore(),
+            noteStore,
+            new CapturingMeetingNoteOpener(),
+            new InMemoryMeetingArtifactStore(),
+            new InMemoryRecordedAudioStore(),
+            new CapturingMeetingSummaryPipeline(),
+            Options.Create(new MeetingAssistantOptions()),
+            NullLogger<MeetingRecordingCoordinator>.Instance,
+            meetingMetadataProvider: new FixedMeetingMetadataProvider(new MeetingMetadata(
+                "Architecture Sync",
+                ["Ada Lovelace (Contoso)"],
+                "",
+                null)),
+            meetingWorkflowEngine: workflowEngine);
+
+        await coordinator.StartAsync(CancellationToken.None);
+        await WaitUntilAsync(() => noteStore.SavedNote?.Frontmatter.Attendees.Count > 0);
+
+        Assert.Equal(["Ada Lovelace"], noteStore.SavedNote?.Frontmatter.Attendees);
+        Assert.Equal(["Ada Lovelace (Contoso)"], workflowEngine.AttendeeRequests);
+
+        await coordinator.StopAsync(CancellationToken.None);
+    }
+
     [Fact]
     public async Task StartSkipsOutlookMeetingAttendeesAboveConfiguredImportLimit()
     {

MeetingAssistant.Tests/TransformingAttendeeWorkflowEngine.cs

@@ -0,0 +1,44 @@
+using MeetingAssistant.Workflow;
+
+namespace MeetingAssistant.Tests;
+
+internal sealed class TransformingAttendeeWorkflowEngine : IMeetingWorkflowEngine
+{
+    private readonly string source;
+    private readonly string replacement;
+
+    public TransformingAttendeeWorkflowEngine(string source, string replacement)
+    {
+        this.source = source;
+        this.replacement = replacement;
+    }
+
+    public List<string> AttendeeRequests { get; } = [];
+
+    public Task RunAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        return Task.CompletedTask;
+    }
+
+    public Task<string> TransformTranscriptLineAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        return Task.FromResult(workflowEvent.TranscriptLineText ?? "");
+    }
+
+    public Task<string> TransformAttendeeAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        AttendeeRequests.Add(workflowEvent.AttendeeName ?? "");
+        return Task.FromResult(string.Equals(workflowEvent.AttendeeName, source, StringComparison.OrdinalIgnoreCase)
+            ? replacement
+            : workflowEvent.AttendeeName ?? "");
+    }
+}

MeetingAssistant.Tests/WorkflowRulesEditorTests.cs

@@ -637,6 +637,28 @@ public sealed class WorkflowRulesEditorTests
         Assert.Equal("rules: []", await File.ReadAllTextAsync(fixture.RulesPath));
     }
 
+    [Fact]
+    public async Task RulesEditorToolsRefuseSideEffectingAttendeeAddedRules()
+    {
+        var fixture = await CreateRulesEditorFixtureAsync();
+
+        var result = await fixture.Tools.WriteRules("""
+            rules:
+            - name: attendee-side-effect
+              on:
+                - attendee_added:
+                    contains: Contoso
+              steps:
+                - uses: add_context
+                  value: '@Model.Attendee.Name'
+            """, replace_file: true);
+
+        Assert.StartsWith("Refused: workflow rules are invalid.", result);
+        Assert.Contains("attendee-side-effect", result);
+        Assert.Contains("attendee.name", result);
+        Assert.Equal("rules: []", await File.ReadAllTextAsync(fixture.RulesPath));
+    }
+
     [Fact]
     public async Task RulesEditorToolsAcceptAndParseMaskedProfanityRedactionRule()
     {

MeetingAssistant/Recording/MeetingRecordingCoordinator.cs

@@ -213,7 +213,12 @@ public sealed class MeetingRecordingCoordinator
             currentMeetingNote = await meetingNoteStore.ReadAsync(currentMeetingNote.Path, cancellationToken);
             if (suppliedMetadata is not null)
             {
-                await ApplyMeetingMetadataAsync(currentMeetingNote, suppliedMetadata, runOptions, cancellationToken);
+                await ApplyMeetingMetadataAsync(
+                    currentArtifacts,
+                    currentMeetingNote,
+                    suppliedMetadata,
+                    runOptions,
+                    cancellationToken);
                 currentMeetingNote = await meetingNoteStore.SaveAsync(
                     currentMeetingNote,
                     runOptions,
@@ -1030,7 +1035,7 @@ public sealed class MeetingRecordingCoordinator
                 }
 
                 var meetingNote = await meetingNoteStore.ReadAsync(run.MeetingNotePath, CancellationToken.None);
-                await ApplyMeetingMetadataAsync(meetingNote, metadata, run.Options, CancellationToken.None);
+                await ApplyMeetingMetadataAsync(run.Artifacts, meetingNote, metadata, run.Options, CancellationToken.None);
                 meetingNote = await meetingNoteStore.SaveAsync(meetingNote, run.Options, CancellationToken.None);
                 if (currentMeetingNote?.Path == meetingNote.Path)
                 {
@@ -1082,6 +1087,7 @@ public sealed class MeetingRecordingCoordinator
     }
 
     private async Task ApplyMeetingMetadataAsync(
+        MeetingSessionArtifacts artifacts,
         MeetingNote meetingNote,
         MeetingMetadata metadata,
         MeetingAssistantOptions options,
@@ -1104,10 +1110,39 @@ public sealed class MeetingRecordingCoordinator
                 return;
             }
 
-            meetingNote.Frontmatter.Attendees = await CanonicalizeAttendeesAsync(metadata.Attendees, cancellationToken);
+            var canonicalized = await CanonicalizeAttendeesAsync(metadata.Attendees, cancellationToken);
+            meetingNote.Frontmatter.Attendees = await TransformAttendeesAsync(
+                artifacts,
+                canonicalized,
+                options,
+                cancellationToken);
         }
     }
 
+    private async Task<List<string>> TransformAttendeesAsync(
+        MeetingSessionArtifacts artifacts,
+        IReadOnlyList<string> attendees,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        var transformed = new List<string>();
+        foreach (var attendee in attendees)
+        {
+            var value = await TransformAttendeeAsync(artifacts, attendee, options, cancellationToken);
+            var storageValue = string.Equals(value, attendee, StringComparison.Ordinal)
+                ? attendee.Trim()
+                : NormalizeAttendeeName(value);
+            var normalized = NormalizeAttendeeName(storageValue);
+            if (!string.IsNullOrWhiteSpace(normalized) &&
+                !transformed.Contains(normalized, StringComparer.OrdinalIgnoreCase))
+            {
+                transformed.Add(storageValue);
+            }
+        }
+
+        return transformed;
+    }
+
     private async Task<List<string>> CanonicalizeAttendeesAsync(
         IReadOnlyList<string> attendees,
         CancellationToken cancellationToken)
@@ -1422,8 +1457,17 @@ public sealed class MeetingRecordingCoordinator
                 continue;
             }
 
+            var transformedDisplayName = await TransformAttendeeAsync(
+                artifacts,
+                match.DisplayName.Trim(),
+                runOptions,
+                cancellationToken);
+            var displayName = string.Equals(transformedDisplayName, match.DisplayName.Trim(), StringComparison.Ordinal)
+                ? match.DisplayName.Trim()
+                : NormalizeAttendeeName(transformedDisplayName);
             var acceptedNames = match.AcceptedNames
                 .Append(match.DisplayName)
+                .Append(displayName)
                 .Select(NormalizeAttendeeName)
                 .Where(name => !string.IsNullOrWhiteSpace(name))
                 .Distinct(StringComparer.OrdinalIgnoreCase)
@@ -1442,7 +1486,6 @@ public sealed class MeetingRecordingCoordinator
                 continue;
             }
 
-            var displayName = match.DisplayName.Trim();
             meetingNote.Frontmatter.Attendees.Add(displayName);
             existingNames.Add(NormalizeAttendeeName(displayName));
             changed = true;
@@ -1502,6 +1545,18 @@ public sealed class MeetingRecordingCoordinator
         return MeetingAttendeeNames.NormalizeDisplayName(attendee);
     }
 
+    private async Task<string> TransformAttendeeAsync(
+        MeetingSessionArtifacts artifacts,
+        string attendee,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        return await meetingWorkflowEngine.TransformAttendeeAsync(
+            MeetingWorkflowEvent.AttendeeAdded(artifacts, attendee),
+            options,
+            cancellationToken);
+    }
+
     private static bool RemoveDuplicateAcceptedAliases(
         List<string> attendees,
         string displayName,

MeetingAssistant/Screenshots/MeetingScreenshotService.cs

@@ -5,6 +5,7 @@ using System.Runtime.InteropServices;
 using System.Text.RegularExpressions;
 using MeetingAssistant.MeetingNotes;
 using MeetingAssistant.Speakers;
+using MeetingAssistant.Workflow;
 
 namespace MeetingAssistant.Screenshots;
 
@@ -149,6 +150,7 @@ public sealed partial class MeetingScreenshotService :
     private readonly IMeetingArtifactStore artifactStore;
     private readonly IMeetingNoteStore meetingNoteStore;
     private readonly ISpeakerIdentityAttendeeCanonicalizer attendeeCanonicalizer;
+    private readonly IMeetingWorkflowEngine meetingWorkflowEngine;
     private readonly IScreenshotOcrClient ocrClient;
     private readonly ILogger<MeetingScreenshotService> logger;
     private readonly ConcurrentDictionary<string, List<PendingOcrTask>> pendingOcrByContext = new(StringComparer.OrdinalIgnoreCase);
@@ -160,12 +162,14 @@ public sealed partial class MeetingScreenshotService :
         IMeetingNoteStore meetingNoteStore,
         ISpeakerIdentityAttendeeCanonicalizer attendeeCanonicalizer,
         IScreenshotOcrClient ocrClient,
-        ILogger<MeetingScreenshotService> logger)
+        ILogger<MeetingScreenshotService> logger,
+        IMeetingWorkflowEngine? meetingWorkflowEngine = null)
     {
         this.screenshotCapture = screenshotCapture;
         this.artifactStore = artifactStore;
         this.meetingNoteStore = meetingNoteStore;
         this.attendeeCanonicalizer = attendeeCanonicalizer;
+        this.meetingWorkflowEngine = meetingWorkflowEngine ?? NoopMeetingWorkflowEngine.Instance;
         this.ocrClient = ocrClient;
         this.logger = logger;
     }
@@ -434,6 +438,7 @@ public sealed partial class MeetingScreenshotService :
                 await AddOcrAttendeesAsync(
                     artifacts,
                     result.Attendees,
+                    options,
                     CancellationToken.None);
             }
         }
@@ -477,6 +482,7 @@ public sealed partial class MeetingScreenshotService :
     private async Task AddOcrAttendeesAsync(
         MeetingSessionArtifacts artifacts,
         IReadOnlyList<string> attendees,
+        MeetingAssistantOptions options,
         CancellationToken cancellationToken)
     {
         var additions = MeetingAttendeeNames.NormalizeDistinct(attendees);
@@ -488,8 +494,13 @@ public sealed partial class MeetingScreenshotService :
         try
         {
             var meetingNote = await meetingNoteStore.ReadAsync(artifacts.MeetingNotePath, cancellationToken);
+            var transformedAdditions = await TransformAttendeesAsync(
+                artifacts,
+                additions,
+                options,
+                cancellationToken);
             var canonicalized = await attendeeCanonicalizer.CanonicalizeAsync(
-                meetingNote.Frontmatter.Attendees.Concat(additions).ToList(),
+                meetingNote.Frontmatter.Attendees.Concat(transformedAdditions).ToList(),
                 cancellationToken);
             if (meetingNote.Frontmatter.Attendees.SequenceEqual(canonicalized, StringComparer.Ordinal))
             {
@@ -512,6 +523,30 @@ public sealed partial class MeetingScreenshotService :
         }
     }
 
+    private async Task<IReadOnlyList<string>> TransformAttendeesAsync(
+        MeetingSessionArtifacts artifacts,
+        IReadOnlyList<string> attendees,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        var transformed = new List<string>();
+        foreach (var attendee in attendees)
+        {
+            var value = await meetingWorkflowEngine.TransformAttendeeAsync(
+                MeetingWorkflowEvent.AttendeeAdded(artifacts, attendee),
+                options,
+                cancellationToken);
+            var normalized = MeetingAttendeeNames.NormalizeDisplayName(value);
+            if (!string.IsNullOrWhiteSpace(normalized) &&
+                !transformed.Contains(normalized, StringComparer.OrdinalIgnoreCase))
+            {
+                transformed.Add(normalized);
+            }
+        }
+
+        return transformed;
+    }
+
     private async Task<bool> ReplaceOcrPlaceholderAsync(
         string assistantContextPath,
         string screenshotId,

MeetingAssistant/Summary/MeetingSummaryTools.cs

@@ -1,6 +1,7 @@
 using MeetingAssistant.MeetingNotes;
 using MeetingAssistant.Speakers;
 using MeetingAssistant.Transcription;
+using MeetingAssistant.Workflow;
 using YamlDotNet.Serialization;
 
 namespace MeetingAssistant.Summary;
@@ -13,6 +14,7 @@ public sealed class MeetingSummaryTools
     private readonly MeetingAssistantOptions options;
     private readonly IDictationWordStore? dictationWordStore;
     private readonly SummaryAgentWriteAudit? writeAudit;
+    private readonly IMeetingWorkflowEngine meetingWorkflowEngine;
     private readonly BoundMeetingProjectResolver projectResolver;
 
     public MeetingSummaryTools(MeetingSessionArtifacts artifacts)
@@ -24,12 +26,14 @@ public sealed class MeetingSummaryTools
         MeetingSessionArtifacts artifacts,
         MeetingAssistantOptions options,
         IDictationWordStore? dictationWordStore = null,
-        SummaryAgentWriteAudit? writeAudit = null)
+        SummaryAgentWriteAudit? writeAudit = null,
+        IMeetingWorkflowEngine? meetingWorkflowEngine = null)
     {
         this.artifacts = artifacts;
         this.options = options;
         this.dictationWordStore = dictationWordStore;
         this.writeAudit = writeAudit;
+        this.meetingWorkflowEngine = meetingWorkflowEngine ?? NoopMeetingWorkflowEngine.Instance;
         projectResolver = new BoundMeetingProjectResolver(options);
     }
 
@@ -98,7 +102,11 @@ public sealed class MeetingSummaryTools
             return "Refused: attendee must not be empty.";
         }
 
-        var displayName = attendee.Trim();
+        var displayName = await meetingWorkflowEngine.TransformAttendeeAsync(
+            MeetingWorkflowEvent.AttendeeAdded(artifacts, attendee.Trim()),
+            options,
+            CancellationToken.None);
+        displayName = displayName.Trim();
         var normalized = MeetingAttendeeNames.NormalizeDisplayName(displayName);
         if (string.IsNullOrWhiteSpace(normalized))
         {

MeetingAssistant/Summary/OpenAiMeetingSummaryAgentPipeline.cs

@@ -1,5 +1,6 @@
 using MeetingAssistant.MeetingNotes;
 using MeetingAssistant.Transcription;
+using MeetingAssistant.Workflow;
 using Microsoft.Agents.AI;
 using Microsoft.Agents.AI.Compaction;
 using Microsoft.Extensions.AI;
@@ -17,6 +18,7 @@ public sealed class OpenAiMeetingSummaryAgentPipeline : IMeetingSummaryPipeline
     private readonly IMeetingSummaryFailureWriter failureWriter;
     private readonly IMeetingSummaryInstructionBuilder instructionBuilder;
     private readonly IDictationWordStore dictationWordStore;
+    private readonly IMeetingWorkflowEngine meetingWorkflowEngine;
 
     public OpenAiMeetingSummaryAgentPipeline(
         IOptions<MeetingAssistantOptions> options,
@@ -25,7 +27,8 @@ public sealed class OpenAiMeetingSummaryAgentPipeline : IMeetingSummaryPipeline
         IServiceProvider services,
         IMeetingSummaryFailureWriter failureWriter,
         IMeetingSummaryInstructionBuilder instructionBuilder,
-        IDictationWordStore dictationWordStore)
+        IDictationWordStore dictationWordStore,
+        IMeetingWorkflowEngine meetingWorkflowEngine)
     {
         this.options = options.Value;
         this.loggerFactory = loggerFactory;
@@ -34,6 +37,7 @@ public sealed class OpenAiMeetingSummaryAgentPipeline : IMeetingSummaryPipeline
         this.failureWriter = failureWriter;
         this.instructionBuilder = instructionBuilder;
         this.dictationWordStore = dictationWordStore;
+        this.meetingWorkflowEngine = meetingWorkflowEngine;
     }
 
     public async Task<MeetingSummaryRunResult> RunAsync(
@@ -51,7 +55,12 @@ public sealed class OpenAiMeetingSummaryAgentPipeline : IMeetingSummaryPipeline
         var agentOptions = options.Agent;
         var key = ResolveApiKey(agentOptions);
         var writeAudit = new SummaryAgentWriteAudit(artifacts);
-        var meetingTools = new MeetingSummaryTools(artifacts, options, dictationWordStore, writeAudit);
+        var meetingTools = new MeetingSummaryTools(
+            artifacts,
+            options,
+            dictationWordStore,
+            writeAudit,
+            meetingWorkflowEngine);
         var tools = CreateTools(meetingTools);
         var instructions = await instructionBuilder.BuildAsync(artifacts, options, cancellationToken);
         using var compactionSummaryClient = new LiteLlmResponsesChatClient(

MeetingAssistant/Workflow/MeetingWorkflowEngine.cs

@@ -17,6 +17,14 @@ public interface IMeetingWorkflowEngine
         MeetingWorkflowEvent workflowEvent,
         MeetingAssistantOptions options,
         CancellationToken cancellationToken);
+
+    Task<string> TransformAttendeeAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        return Task.FromResult(workflowEvent.AttendeeName ?? "");
+    }
 }
 
 public sealed class NoopMeetingWorkflowEngine : IMeetingWorkflowEngine
@@ -38,6 +46,14 @@ public sealed class NoopMeetingWorkflowEngine : IMeetingWorkflowEngine
     {
         return Task.FromResult(workflowEvent.TranscriptLineText ?? "");
     }
+
+    public Task<string> TransformAttendeeAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        return Task.FromResult(workflowEvent.AttendeeName ?? "");
+    }
 }
 
 public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
@@ -54,7 +70,8 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         "state.to",
         "speaker.name",
         MeetingWorkflowRuleSchema.PropertyTranscriptLine,
-        MeetingWorkflowRuleSchema.ParameterTranscriptSpeaker
+        MeetingWorkflowRuleSchema.ParameterTranscriptSpeaker,
+        MeetingWorkflowRuleSchema.PropertyAttendeeName
     ];
 
     private readonly IMeetingWorkflowRulesProvider rulesProvider;
@@ -98,6 +115,21 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
             ?? "";
     }
 
+    public async Task<string> TransformAttendeeAsync(
+        MeetingWorkflowEvent workflowEvent,
+        MeetingAssistantOptions options,
+        CancellationToken cancellationToken)
+    {
+        if (workflowEvent.Type != MeetingWorkflowEventType.AttendeeAdded)
+        {
+            throw new ArgumentException("Workflow event must be an attendee added event.", nameof(workflowEvent));
+        }
+
+        return await RunCoreAsync(workflowEvent, options, cancellationToken)
+            ?? workflowEvent.AttendeeName
+            ?? "";
+    }
+
     private async Task<string?> RunCoreAsync(
         MeetingWorkflowEvent workflowEvent,
         MeetingAssistantOptions options,
@@ -107,7 +139,7 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         var context = new MeetingWorkflowExecutionContext(workflowEvent);
         if (rules.Count == 0)
         {
-            return context.TranscriptLine;
+            return context.ResultValue;
         }
 
         var meeting = await meetingNoteStore.ReadAsync(
@@ -134,10 +166,18 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                 var model = CreateTemplateModel(meeting, context);
                 foreach (var step in rule.Steps)
                 {
+                    if (workflowEvent.Type == MeetingWorkflowEventType.AttendeeAdded &&
+                        !IsAttendeeTransformStep(step))
+                    {
+                        throw new InvalidOperationException(
+                            "attendee_added workflow rules can only transform attendee.name with set_property.");
+                    }
+
                     var stepChanged = await ApplyStepAsync(
                         step,
                         meeting,
                         context,
+                        options,
                         model,
                         cancellationToken);
                     ruleNoteChanged |= stepChanged;
@@ -176,7 +216,7 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                 cancellationToken);
         }
 
-        return context.TranscriptLine;
+        return context.ResultValue;
     }
 
     private static bool MatchesTrigger(
@@ -229,9 +269,41 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                         StringComparison.OrdinalIgnoreCase));
         }
 
+        if (trigger.AttendeeAdded is not null)
+        {
+            return workflowEvent.Type == MeetingWorkflowEventType.AttendeeAdded &&
+                MatchesAttendeeAddedTrigger(trigger.AttendeeAdded, workflowEvent.AttendeeName);
+        }
+
         return false;
     }
 
+    private static bool MatchesAttendeeAddedTrigger(
+        MeetingWorkflowAttendeeAddedTrigger trigger,
+        string? attendeeName)
+    {
+        var attendee = attendeeName ?? "";
+        if (!string.IsNullOrWhiteSpace(trigger.EqualsValue) &&
+            !string.Equals(attendee, trigger.EqualsValue.Trim(), StringComparison.OrdinalIgnoreCase))
+        {
+            return false;
+        }
+
+        if (!string.IsNullOrWhiteSpace(trigger.Contains) &&
+            !attendee.Contains(trigger.Contains.Trim(), StringComparison.OrdinalIgnoreCase))
+        {
+            return false;
+        }
+
+        if (!string.IsNullOrWhiteSpace(trigger.Regex) &&
+            !Regex.IsMatch(attendee, trigger.Regex, RegexOptions.IgnoreCase))
+        {
+            return false;
+        }
+
+        return true;
+    }
+
     private bool EvaluateConditions(
         IReadOnlyList<MeetingWorkflowCondition> conditions,
         MeetingNote meeting,
@@ -298,6 +370,7 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         MeetingWorkflowStep step,
         MeetingNote meeting,
         MeetingWorkflowExecutionContext context,
+        MeetingAssistantOptions options,
         MeetingWorkflowTemplateModel model,
         CancellationToken cancellationToken)
     {
@@ -305,7 +378,11 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         switch (step.Uses.Trim().ToLowerInvariant())
         {
             case MeetingWorkflowRuleSchema.StepAddAttendee:
-                return AddUnique(meeting.Frontmatter.Attendees, value, MeetingAttendeeNames.NormalizeDisplayName);
+                var attendee = await TransformAttendeeAsync(
+                    MeetingWorkflowEvent.AttendeeAdded(context.Event.Artifacts, value),
+                    options,
+                    cancellationToken);
+                return AddUnique(meeting.Frontmatter.Attendees, attendee, MeetingAttendeeNames.NormalizeDisplayName);
             case MeetingWorkflowRuleSchema.StepRemoveAttendee:
                 return RemoveValue(meeting.Frontmatter.Attendees, value);
             case MeetingWorkflowRuleSchema.StepAddProject:
@@ -319,6 +396,9 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
             case MeetingWorkflowRuleSchema.StepSetProperty when IsTranscriptLineProperty(step.Property ?? step.Name):
                 SetTranscriptLine(context, value);
                 return false;
+            case MeetingWorkflowRuleSchema.StepSetProperty when IsAttendeeNameProperty(step.Property ?? step.Name):
+                SetAttendeeName(context, value);
+                return false;
             case MeetingWorkflowRuleSchema.StepSetProperty:
                 return SetProperty(meeting, step.Property ?? step.Name, value);
             default:
@@ -370,11 +450,39 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         context.TranscriptLine = value;
     }
 
+    private static void SetAttendeeName(
+        MeetingWorkflowExecutionContext context,
+        string value)
+    {
+        if (context.Event.Type != MeetingWorkflowEventType.AttendeeAdded)
+        {
+            throw new InvalidOperationException("The attendee.name property can only be set during attendee_added events.");
+        }
+
+        if (string.Equals(context.AttendeeName, value, StringComparison.Ordinal))
+        {
+            return;
+        }
+
+        context.AttendeeName = value;
+    }
+
     private static bool IsTranscriptLineProperty(string? property)
     {
         return MeetingWorkflowRuleSchema.IsProperty(property, MeetingWorkflowRuleSchema.PropertyTranscriptLine);
     }
 
+    private static bool IsAttendeeNameProperty(string? property)
+    {
+        return MeetingWorkflowRuleSchema.IsProperty(property, MeetingWorkflowRuleSchema.PropertyAttendeeName);
+    }
+
+    private static bool IsAttendeeTransformStep(MeetingWorkflowStep step)
+    {
+        return MeetingWorkflowRuleSchema.IsStep(step.Uses, MeetingWorkflowRuleSchema.StepSetProperty) &&
+            IsAttendeeNameProperty(step.Property ?? step.Name);
+    }
+
     private static bool AddUnique(
         List<string> values,
         string value,
@@ -456,7 +564,8 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
             ["state.to"] = workflowEvent.ToState is { } to ? MeetingWorkflowStateNames.ToRuleName(to) : "",
             ["speaker.name"] = workflowEvent.SpeakerName,
             [MeetingWorkflowRuleSchema.PropertyTranscriptLine] = context.TranscriptLine ?? "",
-            [MeetingWorkflowRuleSchema.ParameterTranscriptSpeaker] = workflowEvent.SpeakerName ?? ""
+            [MeetingWorkflowRuleSchema.ParameterTranscriptSpeaker] = workflowEvent.SpeakerName ?? "",
+            [MeetingWorkflowRuleSchema.PropertyAttendeeName] = context.AttendeeName ?? ""
         };
     }
 
@@ -480,7 +589,10 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
                 : new MeetingWorkflowSpeakerModel(workflowEvent.SpeakerName),
             new MeetingWorkflowTranscriptModel(
                 context.TranscriptLine ?? "",
-                workflowEvent.SpeakerName ?? ""));
+                workflowEvent.SpeakerName ?? ""),
+            string.IsNullOrWhiteSpace(context.AttendeeName)
+                ? null
+                : new MeetingWorkflowAttendeeModel(context.AttendeeName));
     }
 
     private sealed class MeetingWorkflowExecutionContext
@@ -489,10 +601,23 @@ public sealed class MeetingWorkflowEngine : IMeetingWorkflowEngine
         {
             Event = workflowEvent;
             TranscriptLine = workflowEvent.TranscriptLineText;
+            AttendeeName = workflowEvent.AttendeeName;
         }
 
         public MeetingWorkflowEvent Event { get; }
 
         public string? TranscriptLine { get; set; }
+
+        public string? AttendeeName { get; set; }
+
+        public string? ResultValue
+        {
+            get
+            {
+                return Event.Type == MeetingWorkflowEventType.AttendeeAdded
+                    ? AttendeeName
+                    : TranscriptLine;
+            }
+        }
     }
 }

MeetingAssistant/Workflow/MeetingWorkflowEvent.cs

@@ -7,7 +7,8 @@ public enum MeetingWorkflowEventType
     Created,
     StateTransition,
     SpeakerIdentified,
-    TranscriptLine
+    TranscriptLine,
+    AttendeeAdded
 }
 
 public sealed record MeetingWorkflowEvent(
@@ -16,7 +17,8 @@ public sealed record MeetingWorkflowEvent(
     AssistantContextState? FromState = null,
     AssistantContextState? ToState = null,
     string? SpeakerName = null,
-    string? TranscriptLineText = null)
+    string? TranscriptLineText = null,
+    string? AttendeeName = null)
 {
     public static MeetingWorkflowEvent Created(MeetingSessionArtifacts artifacts)
     {
@@ -49,4 +51,14 @@ public sealed record MeetingWorkflowEvent(
             SpeakerName: speakerName,
             TranscriptLineText: line);
     }
+
+    public static MeetingWorkflowEvent AttendeeAdded(
+        MeetingSessionArtifacts artifacts,
+        string attendeeName)
+    {
+        return new MeetingWorkflowEvent(
+            MeetingWorkflowEventType.AttendeeAdded,
+            artifacts,
+            AttendeeName: attendeeName);
+    }
 }

MeetingAssistant/Workflow/MeetingWorkflowModels.cs

@@ -37,6 +37,9 @@ public sealed class MeetingWorkflowTrigger
 
     [YamlMember(Alias = "transcript_line")]
     public MeetingWorkflowTranscriptLineTrigger? TranscriptLine { get; set; }
+
+    [YamlMember(Alias = "attendee_added")]
+    public MeetingWorkflowAttendeeAddedTrigger? AttendeeAdded { get; set; }
 }
 
 public sealed class MeetingWorkflowStateTransitionTrigger
@@ -60,6 +63,18 @@ public sealed class MeetingWorkflowTranscriptLineTrigger
     public string? Speaker { get; set; }
 }
 
+public sealed class MeetingWorkflowAttendeeAddedTrigger
+{
+    [YamlMember(Alias = "equals")]
+    public string? EqualsValue { get; set; }
+
+    [YamlMember(Alias = "contains")]
+    public string? Contains { get; set; }
+
+    [YamlMember(Alias = "regex")]
+    public string? Regex { get; set; }
+}
+
 public sealed class MeetingWorkflowCondition
 {
     [YamlMember(Alias = "condition")]
@@ -94,7 +109,8 @@ public sealed record MeetingWorkflowTemplateModel(
     MeetingWorkflowMeetingModel Meeting,
     MeetingWorkflowEventModel Event,
     MeetingWorkflowSpeakerModel? Speaker,
-    MeetingWorkflowTranscriptModel? Transcript);
+    MeetingWorkflowTranscriptModel? Transcript,
+    MeetingWorkflowAttendeeModel? Attendee);
 
 public sealed record MeetingWorkflowMeetingModel(
     string Title,
@@ -111,6 +127,8 @@ public sealed record MeetingWorkflowSpeakerModel(string Name);
 
 public sealed record MeetingWorkflowTranscriptModel(string Line, string Speaker);
 
+public sealed record MeetingWorkflowAttendeeModel(string Name);
+
 internal static class MeetingWorkflowStateNames
 {
     public static string ToRuleName(AssistantContextState state)

MeetingAssistant/Workflow/MeetingWorkflowRuleSchema.cs

@@ -12,13 +12,15 @@ internal static class MeetingWorkflowRuleSchema
     public const string PropertyMeetingTitle = "meeting.title";
     public const string PropertyTranscriptLine = "transcript.line";
     public const string ParameterTranscriptSpeaker = "transcript.speaker";
+    public const string PropertyAttendeeName = "attendee.name";
 
     public static readonly string[] SupportedTriggerKeys =
     [
         "created",
         "state_transition",
         "speaker_identified",
-        "transcript_line"
+        "transcript_line",
+        "attendee_added"
     ];
 
     public static readonly string[] SupportedConditionKeys =
@@ -42,7 +44,8 @@ internal static class MeetingWorkflowRuleSchema
     [
         PropertyTitle,
         PropertyMeetingTitle,
-        PropertyTranscriptLine
+        PropertyTranscriptLine,
+        PropertyAttendeeName
     ];
 
     public static bool IsStep(string? value, string step)

MeetingAssistant/Workflow/MeetingWorkflowRulesValidator.cs

@@ -59,7 +59,8 @@ internal static class MeetingWorkflowRulesValidator
             trigger.Created is not null,
             trigger.StateTransition is not null,
             trigger.SpeakerIdentified is not null,
-            trigger.TranscriptLine is not null);
+            trigger.TranscriptLine is not null,
+            trigger.AttendeeAdded is not null);
         if (configuredCount == 0)
         {
             errors.Add($"{ruleName} on[{triggerIndex + 1}] must contain one supported trigger: {JoinAllowed(MeetingWorkflowRuleSchema.SupportedTriggerKeys)}.");
@@ -137,6 +138,12 @@ internal static class MeetingWorkflowRulesValidator
             return;
         }
 
+        if (HasAttendeeAddedTrigger(rule) &&
+            !IsAttendeeNameSetPropertyStep(step))
+        {
+            errors.Add($"{stepPath} on attendee_added rules can only transform the attendee with 'set_property' property 'attendee.name'.");
+        }
+
         if (MeetingWorkflowRuleSchema.IsStep(uses, MeetingWorkflowRuleSchema.StepSetProperty))
         {
             var property = step.Property ?? step.Name;
@@ -153,6 +160,11 @@ internal static class MeetingWorkflowRulesValidator
             {
                 errors.Add($"{stepPath} can set 'transcript.line' only on rules with a transcript_line trigger.");
             }
+            else if (MeetingWorkflowRuleSchema.IsProperty(property, MeetingWorkflowRuleSchema.PropertyAttendeeName) &&
+                !HasAttendeeAddedTrigger(rule))
+            {
+                errors.Add($"{stepPath} can set 'attendee.name' only on rules with an attendee_added trigger.");
+            }
         }
 
         if (step.Value is { } value &&
@@ -181,6 +193,17 @@ internal static class MeetingWorkflowRulesValidator
         return rule.On.Any(static trigger => trigger.TranscriptLine is not null);
     }
 
+    private static bool HasAttendeeAddedTrigger(MeetingWorkflowRule rule)
+    {
+        return rule.On.Any(static trigger => trigger.AttendeeAdded is not null);
+    }
+
+    private static bool IsAttendeeNameSetPropertyStep(MeetingWorkflowStep step)
+    {
+        return MeetingWorkflowRuleSchema.IsStep(step.Uses, MeetingWorkflowRuleSchema.StepSetProperty) &&
+            MeetingWorkflowRuleSchema.IsProperty(step.Property ?? step.Name, MeetingWorkflowRuleSchema.PropertyAttendeeName);
+    }
+
     private static int CountConfigured(params bool[] values)
     {
         return values.Count(static value => value);
@@ -206,7 +229,8 @@ internal static class MeetingWorkflowRulesValidator
             new MeetingWorkflowSpeakerModel("Ada Lovelace"),
             new MeetingWorkflowTranscriptModel(
                 "[00:00:01] Ada Lovelace: Validation line.",
-                "Ada Lovelace"));
+                "Ada Lovelace"),
+            new MeetingWorkflowAttendeeModel("Ada Lovelace"));
     }
 
     private static string FormatRazorValidationMessage(Exception exception)

README.md

@@ -130,7 +130,7 @@ See `docs/meeting-assistant-configuration.md` for the full configuration referen
 
 ## Workflow Rules And Agents
 
-Meeting-specific automation lives in a local YAML file, not in committed personal rules. Rules can trigger on meeting creation, assistant-context state transitions, identified speakers, and transcript-line writes. They can add/remove attendees, set supported properties, add context, add projects, and rewrite a transcript line before persistence.
+Meeting-specific automation lives in a local YAML file, not in committed personal rules. Rules can trigger on meeting creation, assistant-context state transitions, identified speakers, transcript-line writes, and added attendees. They can add/remove attendees, set supported properties, add context, add projects, rewrite a transcript line, and transform an attendee name before it is stored.
 
 The tray menu exposes `Open agent`, which opens the `Meeting Summary Agent` window. It can edit workflow rules with validation, inspect logs and health/status, manage speaker identities and samples, run ASR diagnostics, and read/write scoped meeting/project artifacts through explicit tools.
 

docs/meeting-workflow-engine.md

@@ -71,6 +71,12 @@ The engine runs when `MeetingRecordingCoordinator` emits a meeting workflow even
 - `state_transition`: after the assistant context state moves forward.
 - `speaker_identified`: when live or final speaker identification reports a display name.
 - `transcript_line`: after a formatted live transcript line is durably appended, before any changed line is rewritten in place, and before lines are used in full transcript rewrites.
+- `attendee_added`: before a newly added attendee is stored in the meeting note.
+
+`attendee_added` is emitted only by Meeting Assistant code paths that intentionally add an attendee
+through the workflow engine, notification actions, OCR/screenshot processing, summarizer tools, or
+other attendee-add operations. Direct edits to a meeting note file, including direct artifact/frontmatter
+repair writes by an agent, are left verbatim and do not trigger attendee automation.
 
 When a recording is started by accepting a calendar notification, the cached appointment metadata is applied before the `created` event. Rules still receive the normal `created` event and the normal `collecting metadata` to `transcribing` state transition, but they see the accepted appointment title, attendees, agenda, and scheduled end instead of a generated placeholder or a separate Outlook current-meeting lookup result.
 
@@ -162,6 +168,22 @@ on:
       speaker: Guest-1
 ```
 
+### `attendee_added`
+
+Runs before a newly added attendee is stored. `equals`, `contains`, and `regex` filters are optional; omitted filters match any attendee. `equals` and `contains` are case-insensitive.
+
+```yaml
+on:
+  - attendee_added:
+      contains: Contoso
+```
+
+```yaml
+on:
+  - attendee_added:
+      regex: '@contoso\.com>$'
+```
+
 ## Conditions
 
 Conditions use NCalc expressions. Dotted workflow variables may be written directly; the engine rewrites them into NCalc parameters internally.
@@ -184,6 +206,7 @@ Available condition variables:
 - `speaker.name`
 - `transcript.line`
 - `transcript.speaker`
+- `attendee.name`
 
 Available helper functions:
 
@@ -217,6 +240,7 @@ Step `value` fields can be plain strings or Razor templates. Razor templates rec
 - `Model.Speaker.Name`
 - `Model.Transcript.Line`
 - `Model.Transcript.Speaker`
+- `Model.Attendee.Name`
 
 Example:
 
@@ -259,7 +283,11 @@ steps:
 
 ### `set_property`
 
-Sets a supported property. Supported meeting properties are `title` and `meeting.title`. During `transcript_line` events, `transcript.line` is also supported. For live transcription, changing `transcript.line` rewrites the referenced formatted line after the workflow task completes.
+Sets a supported property. Supported meeting properties are `title` and `meeting.title`. During `transcript_line` events, `transcript.line` is also supported. During `attendee_added` events, `attendee.name` is supported. For live transcription, changing `transcript.line` rewrites the referenced formatted line after the workflow task completes. For attendee additions, changing `attendee.name` stores the transformed attendee instead of the original added value.
+
+Rules triggered by `attendee_added` are transformation-only: their steps must use `set_property`
+with `property: attendee.name`. They can still use trigger filters, conditions, and Razor templates
+to decide and compute the transformed value, but they cannot perform note/context side effects.
 
 ```yaml
 steps:
@@ -275,6 +303,13 @@ steps:
     value: '@Model.Transcript.Line.Replace("*****", "[redacted]")'
 ```
 
+```yaml
+steps:
+  - uses: set_property
+    property: attendee.name
+    value: '@Model.Attendee.Name.Replace(" (Contoso)", "")'
+```
+
 ### `add_context`
 
 Appends rendered text to the assistant context artifact body. This step does not count as a meeting-note mutation and does not cause a meeting-note save by itself.
@@ -370,6 +405,20 @@ rules:
       value: '@Model.Transcript.Line.Replace("*****", "[redacted]")'
 ```
 
+Clean attendee names as they are added:
+
+```yaml
+rules:
+- name: clean-contoso-attendees
+  on:
+    - attendee_added:
+        contains: Contoso
+  steps:
+    - uses: set_property
+      property: attendee.name
+      value: '@Model.Attendee.Name.Replace(" (Contoso)", "")'
+```
+
 ## Implementation Notes
 
 Core files:

openspec/changes/archive/2026-07-01-transform-added-attendees/.openspec.yaml

@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-07-01

openspec/changes/archive/2026-07-01-transform-added-attendees/design.md

@@ -0,0 +1,30 @@
+# Design
+
+## Event Model
+
+Add a workflow event type, `attendee_added`, that carries the attendee string being added. The event is used as a transformation hook before a caller stores the attendee in the meeting note. Rules can match the event with `equals`, `contains`, or `regex` trigger filters over the current attendee value.
+
+## Transformation Contract
+
+The workflow engine exposes `TransformAttendeeAsync`, mirroring `TransformTranscriptLineAsync`. During `attendee_added` events:
+
+- conditions can read `attendee.name`,
+- Razor templates can read `Model.Attendee.Name`,
+- `set_property attendee.name` mutates the attendee value returned to the caller.
+
+Other workflow steps keep their existing semantics, but the intended transformation path is `set_property attendee.name`.
+Rules triggered by `attendee_added` are limited to that transformation path so the value transform does not hide unrelated note or context side effects.
+
+Direct meeting note file edits remain outside the workflow event model. If a user or agent writes a meeting note file/frontmatter directly, Meeting Assistant preserves that content verbatim and does not emit `attendee_added`.
+
+## Call Sites
+
+Callers transform attendee candidates before writing them:
+
+- metadata and accepted prompt metadata after canonicalization,
+- workflow `add_attendee` steps before de-duplication,
+- screenshot OCR candidates before canonicalization and merge,
+- summary-agent `add_attendee` tool calls before duplicate checks and note writes,
+- speaker identity attendee additions before adding matched names.
+
+Unchanged metadata attendees preserve the existing canonicalizer output, including email display strings.

openspec/changes/archive/2026-07-01-transform-added-attendees/proposal.md

@@ -0,0 +1,17 @@
+## Why
+
+Attendees enter Meeting Assistant from several paths: calendar metadata, accepted recording prompts, workflow actions, screenshot OCR, speaker identity updates, and summarizer add-attendee tools. Today those paths can normalize display names, but they cannot apply local transformation rules such as trimming company suffixes, replacing aliases, or cleaning attendee strings consistently.
+
+## What Changes
+
+- Add an `attendee_added` workflow trigger that runs whenever Meeting Assistant adds an attendee to a meeting note.
+- Allow `attendee_added` triggers to filter the added attendee with full equality, substring, or regex matching.
+- Expose `attendee.name` to workflow conditions and Razor templates.
+- Allow `set_property` to update `attendee.name` during `attendee_added` events, mirroring transcript-line transformation.
+- Apply attendee transformations to attendees added by metadata import, prompted-start metadata, workflow `add_attendee`, screenshot OCR, and summary/workflow editor agent tools.
+
+## Impact
+
+- Workflow engine, rules schema validation, and workflow documentation.
+- Attendee write paths in recording metadata, screenshot OCR, summary tools, and workflow actions.
+- Behavior tests for workflow transformation and representative attendee-add sources.

openspec/changes/archive/2026-07-01-transform-added-attendees/specs/meeting-session/spec.md

@@ -0,0 +1,29 @@
+## MODIFIED Requirements
+
+### Requirement: Meeting automation rules support lifecycle triggers
+Meeting Assistant SHALL support rule triggers for `created`, `state_transition`, `speaker_identified`, `transcript_line`, and `attendee_added`.
+
+An `attendee_added` trigger MAY filter by `equals`, `contains`, or `regex` against the attendee value being added. `equals` and `contains` filters SHALL match case-insensitively.
+
+Meeting Assistant SHALL apply attendee-added transformations before storing attendees added from meeting metadata, accepted recording-prompt metadata, workflow `add_attendee` steps, screenshot OCR, speaker identity updates, and summarizer add-attendee tools.
+
+#### Scenario: Attendee added rule filters and transforms a metadata attendee
+- **GIVEN** a configured rule that triggers on added attendees containing `@contoso.com`
+- **AND** the rule sets `attendee.name` to a display name derived from the added attendee
+- **WHEN** Meeting Assistant adds attendee `Ada Lovelace <ada@contoso.com>` from meeting metadata
+- **THEN** the stored meeting attendee is the transformed attendee name
+- **AND** the original attendee string is not stored
+
+### Requirement: Meeting automation rules support conditions and steps
+Meeting Assistant SHALL expose the added attendee name to `attendee_added` rule conditions and Razor step templates as `attendee.name`.
+
+The `set_property` step SHALL support setting `attendee.name` during `attendee_added` events.
+
+Rules with an `attendee_added` trigger SHALL be limited to transforming `attendee.name` with `set_property`.
+
+Direct meeting note file writes SHALL NOT emit `attendee_added` or transform attendee values.
+
+#### Scenario: Attendee added rules can use regex and Razor
+- **GIVEN** a configured `attendee_added` rule with a regex filter over the added attendee
+- **WHEN** Meeting Assistant adds an attendee matching the regex
+- **THEN** the rule can set `attendee.name` with a Razor template using `Model.Attendee.Name`

openspec/changes/archive/2026-07-01-transform-added-attendees/tasks.md

@@ -0,0 +1,8 @@
+# Tasks
+
+- [x] Add OpenSpec scenarios for attendee-added trigger filtering and transformation.
+- [x] Add a failing workflow-engine behavior test for transforming an added attendee through `attendee_added`.
+- [x] Implement attendee-added workflow event, trigger filters, `attendee.name` condition/template value, and `set_property attendee.name`.
+- [x] Apply attendee transformations from metadata/prompted starts, workflow `add_attendee`, screenshot OCR, and agent attendee tools.
+- [x] Update workflow engine documentation.
+- [x] Run focused tests plus `openspec validate transform-added-attendees --strict`.

openspec/specs/meeting-session/spec.md

@@ -221,105 +221,32 @@ Meeting Assistant SHALL expose a diagnostic endpoint that reloads application co
 - **AND** future workflow events use the reloaded workflow automation configuration
 
 ### Requirement: Meeting automation rules support lifecycle triggers
-Meeting Assistant SHALL support rule triggers for `created`, `state_transition`, `speaker_identified`, and `transcript_line`.
+Meeting Assistant SHALL support rule triggers for `created`, `state_transition`, `speaker_identified`, `transcript_line`, and `attendee_added`.
 
-A `state_transition` trigger MAY filter by `from`, `to`, or both state values.
+An `attendee_added` trigger MAY filter by `equals`, `contains`, or `regex` against the attendee value being added. `equals` and `contains` filters SHALL match case-insensitively.
 
-A `speaker_identified` trigger MAY filter by speaker name.
+Meeting Assistant SHALL apply attendee-added transformations before storing attendees added from meeting metadata, accepted recording-prompt metadata, workflow `add_attendee` steps, screenshot OCR, speaker identity updates, and summarizer add-attendee tools.
 
-A `transcript_line` trigger MAY filter by speaker name.
+#### Scenario: Attendee added rule filters and transforms a metadata attendee
-
+- **GIVEN** a configured rule that triggers on added attendees containing `@contoso.com`
-Workflow rule execution SHALL log each triggered rule with its rule name and event type.
+- **AND** the rule sets `attendee.name` to a display name derived from the added attendee
-
+- **WHEN** Meeting Assistant adds attendee `Ada Lovelace <ada@contoso.com>` from meeting metadata
-Workflow rule execution SHALL log rule failures with the rule name and event type.
+- **THEN** the stored meeting attendee is the transformed attendee name
-
+- **AND** the original attendee string is not stored
-#### Scenario: State transition rule matches from and to
-- **GIVEN** a configured rule that triggers on a state transition from `collecting metadata` to `transcribing`
-- **WHEN** Meeting Assistant transitions that meeting from `collecting metadata` to `transcribing`
-- **THEN** it applies the rule steps
-
-#### Scenario: Speaker identified rule filters by name
-- **GIVEN** a configured rule that triggers when speaker `Ada` is identified
-- **WHEN** Meeting Assistant identifies speaker `Grace`
-- **THEN** it does not apply the rule
-- **WHEN** Meeting Assistant identifies speaker `Ada`
-- **THEN** it applies the rule steps
-
-#### Scenario: Transcript line rule rewrites masked profanity after durable append
-- **GIVEN** a configured rule that triggers on transcript line writes and sets `transcript.line` by replacing `*****` with `[redacted]`
-- **WHEN** Meeting Assistant writes a transcript line for speaker `Guest-1` containing `*****`
-- **THEN** Meeting Assistant first appends the original formatted line to the transcript file
-- **AND** rewrites that written line to contain `[redacted]`
-- **AND** the final written transcript line does not contain `*****`
-
-#### Scenario: Transcript line workflow failure keeps transcript writing
-- **GIVEN** a configured transcript line workflow rule fails while processing a transcript line
-- **WHEN** Meeting Assistant receives that live transcript segment
-- **THEN** Meeting Assistant keeps the original formatted line in the transcript file
-- **AND** logs the workflow rule failure
-- **AND** continues processing later transcript segments
 
 ### Requirement: Meeting automation rules support conditions and steps
-Meeting Assistant SHALL support rule conditions using an expression engine.
+Meeting Assistant SHALL expose the added attendee name to `attendee_added` rule conditions and Razor step templates as `attendee.name`.
 
-Rules SHALL support nested `and`, `or`, and `not` condition groups.
+The `set_property` step SHALL support setting `attendee.name` during `attendee_added` events.
 
-Step values SHALL support Razor syntax against the current meeting event model.
+Rules with an `attendee_added` trigger SHALL be limited to transforming `attendee.name` with `set_property`.
 
-Rendered step values SHALL be treated as plain UTF-8 text for markdown artifacts and SHALL NOT persist Razor HTML entity encoding.
+Direct meeting note file writes SHALL NOT emit `attendee_added` or transform attendee values.
 
-Step values SHALL treat `@` characters inside valid email address tokens as literal text rather than Razor transitions.
+#### Scenario: Attendee added rules can use regex and Razor
-
+- **GIVEN** a configured `attendee_added` rule with a regex filter over the added attendee
-Meeting Assistant SHALL expose the formatted transcript line and transcript speaker to `transcript_line` rule conditions and Razor step templates.
+- **WHEN** Meeting Assistant adds an attendee matching the regex
-
+- **THEN** the rule can set `attendee.name` with a Razor template using `Model.Attendee.Name`
-Meeting Assistant SHALL support these initial rule steps:
-
-- `add_attendee`
-- `remove_attendee`
-- `set_property`
-- `add_context`
-- `add_project`
-
-The `set_property` step SHALL support setting `transcript.line` during `transcript_line` events.
-
-#### Scenario: Nested conditions choose a matching rule
-- **GIVEN** a configured rule with nested `and`, `or`, and `not` conditions over meeting title, attendees, and event data
-- **WHEN** the condition evaluates to true
-- **THEN** Meeting Assistant applies the rule
-- **WHEN** the condition evaluates to false
-- **THEN** Meeting Assistant skips the rule
-
-#### Scenario: Templated context mentions identified speaker
-- **GIVEN** a configured `speaker_identified` rule with an `add_context` step using Razor syntax
-- **WHEN** Meeting Assistant identifies matching speaker `Ada`
-- **THEN** it appends rendered context text containing `Ada` to the assistant context note
-
-#### Scenario: Email addresses do not trigger Razor templating
-- **GIVEN** a configured rule step value containing `Support@contoso.com`
-- **WHEN** the rule runs
-- **THEN** Meeting Assistant preserves the email address as literal text
-
-#### Scenario: Email addresses can appear beside Razor templating
-- **GIVEN** a configured rule step value containing both `Support@contoso.com` and a Razor expression
-- **WHEN** the rule runs
-- **THEN** Meeting Assistant renders the Razor expression and preserves the email address as literal text
-
-#### Scenario: Razor-rendered transcript line preserves UTF-8 text
-- **GIVEN** a configured `transcript_line` rule uses Razor to replace part of a transcript line containing `heißt`, `Schimpfwörter`, and `nächstes`
-- **WHEN** the rule changes `transcript.line`
-- **THEN** the resulting transcript line contains the original UTF-8 characters
-- **AND** does not contain HTML entities such as `&#xDF;`, `&#xF6;`, or `&#xE4;`
-
-#### Scenario: Rule can clean a meeting title
-- **GIVEN** a configured state-transition rule that matches a title containing a configured marker
-- **WHEN** the rule runs
-- **THEN** Meeting Assistant can update the meeting title through `set_property`
-
-#### Scenario: Transcript line conditions can use the written line and speaker
-- **GIVEN** a configured `transcript_line` rule with conditions over `transcript.line` and `transcript.speaker`
-- **WHEN** Meeting Assistant writes a transcript line that matches both conditions
-- **THEN** Meeting Assistant applies the rule steps after the original formatted line is durably appended
-- **AND** rewrites the written line if a rule changes `transcript.line`
 
 ### Requirement: Workflow rules and speaker identities can be edited through a tray-launched assistant
 Meeting Assistant SHALL expose an `Open agent` item from the tray icon menu.